Pump assembly



April 6, 1948- R. R. CURTIS ETAL 2,439,241

PUMP ASSEMBLY Filed Feb. 6, 1943 Patented Apr. 6, 1948 PUMP ASSEMBLY l Russell R. Curtis and Richard L. Gates, Dayton,

Ohio, assignors to Curtis Pump Company, Dayton, Ohio, a corporationv of Ohio Application February 6, 1943, Serial No. 474,969

4 Claims. (Cl. 103.136)

This'invention relates to pump constructions and particularly to the arrangement of pumping and sealing means in a casing so thata cover for the casing will hold the means in operative assembly, which cover, in turn, can be clamped between a ange on the casing and a mounting block for the pump such as an engine pad.

A feature of this invention is the utilization` `invention is not limited to such an embodiment since it includes within its scope all types of pumps, blowers and the like having the constructions deiined by the appended claims.

It is'an object of this invention to provide an inexpensive, readily assembled, lightweight pump.

A further object of this invention is to provide a construction including parts mounted in a `casing and held in operative assembled relation in the casing by a cover which cover, in turn, is adapted to be clamped between the casing and a mounting part for the casing.

A further object of the invention is` to provide pumps adapted for direct mounting on an airplane engine to supply fuel to the engine which pumps include a metal casing and a thermosetting synthetic plastic cover for said casing adapted to be clamped between the casing and engine.

A still further object of the invention is to provide airplane engine fuel pumps with thermosetting synthetic plastic covers which hold the pump parts in assembled operative relation in a housing.

A further object of the invention is to provide a rotary vane-type pump wherein the pump housing forms a thrust face for one of the pump rotor bearings, the pump liner thrusts against this bearing, a second bearing is held in proper spaced relation from the rst mentioned bearing by the liner, a spacer sleeve thrusts against this second bearing to provide a chamber for pump seal parts in the casing, a, stationary seal ring thrusts against the spacer sleeve, and a skirt on an end cap for the open end of the casing holds all of the aforementioned elements in such thrusting relationship. t

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheet of drawings, which, by way of preferred example only, illustrates one embodiment of the invention.

On the drawings: l

Figure 1 is a fragmentary elevational view, with parts broken, away and shown in vertical cross section, `of a pump according to this invention mounted on an engine.

Figure 2 is a longitudinal cross-sectional view of the pump shown in Figure 1. y

Figure 3 is an end elevational view illustrating the cover for the pump shown in Figures 1 and 2.

As shown on the drawings:

As shown in Figure 1, the pump I0 of this invention is mounted on an engine E, such as an alrplane engine having a pad P providing a fiat mounting face P1 around a chamber C in the engine in which is mounted a driver D such as one of the driven shafts of the engine E. 'I'he driver D has a socket end D1 which is preferably internally splined as at D2 to receive the splined end of the pump drive shaft as will be more fully hereinafter described.

Studs S are tapped into the pad P of the engine E and project from the flat face P1 thereof. Four such studs S are preferably disposed symmetrically about the opening of the engine chamber C.

As best shown in Figure 2, the pump I0 is composed of a casing or housing II. The casing or housing II can be formed of metal and defines a,

provide drain outlets communicating with the interior of the casing as will be more fully hereinafter described.

The closed end Ila of the casing provides a thrust, face which receives a first bearing ring I4. This bearing ring can be composed of graphitic carbon.

A liner I5, preferably of metal, is next mounted in the casing Il to define, with its inner surface I5a thereof, the pump bore. The liner I5, of course, has a cylindrical outer surface I5b snugly tting the cylindrical inner wall of the casing.

In order to prevent rotation of the liner I5 in the casing, the liner preferably has a slot I 6 cut in the outer face thereof to receive a pin Il pressed through a hole IIc in a side wall of the casing. The liner I5 is'thus held against rotation and in proper relationship to the uid inlet and outlet for the pump An inlet I of the pump is shown in Figure l.

A second bearing ring I8, which can also be composed of graphitic carbon, is seated in the easing II againstthe other end of the liner I5.

A spacer sleeve I9 is mounted in the casing I I against the second bearing ring IB. This spacer sleeve can be composed of metal or lightweight plastic.

, 3 The sleeve I9 preferably has a beveledend I9a cooperating with the inner wall of the housing H to provide a recess for a packing ring or gasket 20 of resilient material.

A stationary seal ring 2I is next mounted in the lcasing II and is seated on the gasket 20. This stationary seal ring can be composed of graphitic carbon or can be of composite structure having an active sealing face 2| a composed of graphitic carbon.

In accordance with this invention, the open end of the casing I is closed with a cover 22 adapted to hold al1 of the parts I4, I5,` I8, I9, 20 and 2I in operative thrusting relation. This cover 22, because of the manner in which it is clamped when mounted on the engine'E as shown in Figure 1, can be composed of lightweight plastic such as a hard, thermoset synthetic resin having heatresisting properties.v

Thecover 22 has a raised pilot portion 22a surrounded by a marginal portion 22h .adapted to overlie the flange IIb of the casing. yThis marginal portion 22h, as shown in Figure 3, is of substantially square shape with rounded corners and has apertures 23 adjacent the rounded corners adapted to receive the studs S on the engine as will be hereinafter described. The cover 22 is secured on the flange I Ib with the apertures 23 aligned with similar apertures 24 (Figure 1) in the flange IIb of the casing by means of two ,thrust loads when the pump is operatively mounted on the engine'pad P.

The cover 22 has a cylindrical depending skirt portion 22e fitting in the open end of the casing II as best shown in Figure 2. This skirt portion 22e thrusts against the stationary seal ring 2I but can be recessed at intervals around the free end thereof asv at 26 so that ports will be provided joining the space 21 in the casing between the cover and seal ring 2I with one of the drain ports i3. y

A rotor\28 has reduced diameter cylindrical ends 28a and 28h respectively seated in the first and second bearing rings I4 and I8. This rotor 28 thus has shoulders 28o adapted to be thrust against the inner faces of the bearing rings.

The rotor is slotted as at 28d between the shoulders 28e to carry the usual sliding pumping vanes for cooperating with the inner wall I 5a of the liner I5.

It will be understood, of course, that fluid is fed through a port (not shown) in the liner I5 from the inlet I and is discharged by the vanes through another port (not shown) in the liner out of an outlet in the pump casing (not shown). It should also be understood that a by-pass and relief valve arrangement can be mounted on the pump casing I I in a manner similar to that shown in the Russell R. Curtis Patent 2,268,805, dated `January 6, 1942. The end portion 28h of the rotor 28 is intersleeve I9, thence through an aperture in the stationary seal ring 2|, through the chamber 21, and through an opening 22d in the cover to terminate in another splined end 30h outside of the pump. This splined end 30h is adapted to be seated in the lsplined socket Di of the engine driver D as shown in Figure 1.

The pump shaft 39 has an integral collaror radial fiange 30e thereon in the chamber 3|. A rotating seal ring 32, which is preferably composed of metal such asNitralloy, is disposed bei tween the collar 36e and the sealing face 2Ia of the stationary seal ring 2l. This rotating seal ring 32 has a metal cover 33 crimped therearound which is urged by a spring 34 held under 'comf pression between a retainer bottomed on the rotor-'portion 28h and ti e cover 33 to urge the ring 32 against the ring 2l The splines 29 and 30a are preferably of involute construction so that the pump shaft-30 can rock in the rotor in the event of misalignment between the rotor and driver D of the engine.

The seal arrangement is claimed in our United states Patent 2,380,222, granted July 1o, 194s, and is such that the shaft 30 can be rocked or axially moved without unseating the seal ring and without permitting leakage between the collar 30e and ring 32. flexible diaphragm 36 has an outer marginal portion thereof clamped by the cover 33 tightly against the rotating seal ring 32 together with inner marginal portion clamped by a sleeve 31 pressed on the pump shaft 30 against the collar 30e. With this arrangement, and with the pressure of the spring 34 being directed on the outer marginal portion of the rotating seal ring 32, the collar 30e of the pump shaft could be cocked oi of the rotating seal ring 32 without permitting leakage from the chamber 3| into the chamber 2I because the diaphragm 36 will, of course, prevent this leakage. Therefore, the pump shaft 30 could move axially, wobble or rock without causing leakage and without effecting unseating of the rotating seal ring off of the stationary seal r ng. i

In the event, however, that any leakage did occur into the chamber 21, the leaked-in fluid could be drained through the port 26 in the cover into a drain line adapted to be tapped into the port I3.

As shown in Figure 1, the pilot portion 22a of the cover 22 is adapted to be seated in the chamber C o f the engine E with the marginal portion 22h of the cover seated on the fiat face P1 of the pad and receiving the studs S through the aper` ture 23 thereof. The studs also project through the apertures such as 24 of the casing flange IIb and receive nuts N. The nuts N draw thecasing flange II b toward the pad P and thus clamp the cover between the at face Pi of the pad and the casing flange IIb. The at heads of the screws 25 will, of course, not interfere .-with a full seating of the marginal portion 22h of the cover on the pad face P1. In operation, therefore, the cover 22 is clamped between the mounting means and the casing flange and effectively supported there- To prevent such leakage a casing against the end wall lia thereof. The rotor can then be seated to position its end 28a into the bearing ring i4. The liner I5 can be slid into the casing around the rotor andthe second bearing ring I8 then slipped inthe casing aroud the part 28h of the rotor. Obviously, of course, an assembly including the bearing rings, the rotor and vanes and the liner could be slipped into they casing as a unit. The pump shaft30 is vmerely slid in position in the member 28h of the rotor and can have the rotating seal construction already mounted thereon. The spacer sleeve I9 is merely slid into the casing `followed by the packing ring and the stationary seal ring.

The pumps of this invention are lightweight, compact, very inexpensive, and easily assembled.

It will, of course, be understood that various details of construction may be varied through a -wide range Without departing'from the principles of this invention and it is, therefore not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

We claim as our invention:

1. In a pump and engine assembly including an engine having an apertured mounting pad, studs projecting from the pad around the aperture, `and nuts threaded on the studs, the improvements of a pump casing having a closed end and an open end with an outturned flange therearound, a rst bearing ring in the casing at the closed end thereof, a pump liner in the casing having one end against said first bearing ring, a second bearingring in the casing against the other end of the liner, a spacer sleeve slidably fitting on the interior wall of the casing having one end against the second bearing ring, a resilient gasket in the casing at the other end of the sleeve, a stationary seal ring in the casing seated against the gasket, a cover for the open end of the casing having a peripheral portion overlying the casing flange, a skirt portion extending into the casing to thrustagainst the stationary seal ring thereby imparting'the sole thrusting force for holding said bearing rings, pump liner, spacer sleeve, and seal ring together, and an external pilot portion seating in the aperture of the'engine' pad, a rotor having reduced diameter end portions in said first and second bearing rings, a

shaft splined in that portion of the rotor which is seated in the second bearing ring, a rotatable seal on the shaft, means urging the rotatable seal against the stationary seal ring, said peripheral portion of the cover and said casing flange having ings in said casing, pumping means in saidcasing rotatably supported by said bearings, a drive shaft extending into said casing through the open end thereof and having an inner end roekably connected to said pumping means, a stationary seal ring means slidably` tting on the interior wall of the casing and surrounding the drive shaft in spaced relation therefrom,.and a rotating seal ring sealingly connectedto said drive shaft and having a face portion in sliding sealing engagement with the stationary seal ring means,

. tionary sealing ring means, and a cover remov between said stationary seal ring means and one of said bearings and in contact therewith, and a cover for said open end of the casing having a r flange portion overlying the outturned flange of 1 the casing and a ski-rt portion slidably fitting on the interior wall of the casing and having an end face contacting said stationary seal ring means to cooperate in opposed relation to the end thrust face of the casing for carrying/all thrust loads on the pumping means and stationary seal ring means.

3. A pump construction comprising a casing having an open end and a closed end, pumping means in said casing bottomed on the closed end thereof and terminating inwardly from the open end thereof, a drive shaft in said'casingprojecting through the open end thereof and rockably splined to said pumping means for driving the `pumping means, a spacer sleeve slidably mounted in said casing in spaced relation around said drive shaft and bottomed on said pumping means, stationary seal ring means bottomed on said spacer sleeve, said stationary seal ring means slidably fitting the interior of said casing and surrounding the drive shaft in spaced relation therefrom, rotating seal ring means sealingly connected to said drive shaft and having a face in sliding sealing contact with the stationary seal ring means, .and an apertured cover closing the open end of said casing and receiving the drive shaft freely therethrough, said cover having an end" faced portion thrusting Yagainst said stationary seal ring means to coact with said spacer sleeve and said pump means in the casing for clamping the stationary seal ring means in position in the casing and for coacting with the closed end of the casing to carry all thrust loads of the parts in the casing.

4. A pump comprising a casing, spaced bearings in said casing, pumping means in said casing rotatably supported by said bearings, a drive shaft rockably splined to said pumping means and having a projecting portion, a rotatable sealing ring supported by said projecting portion, a flexible diaphragm extending from said projecting portion to said sealing ring, stationary sealing ring means in sliding sealing engagement with said rotatable sealing ring and slidably fitting on the interior Wall of .said casing, a spacer ring bottomed on one of said bearings and disposed in said casing between said bearing and said sta- 'ably secured to said casing and having a depending skirt portion extending into the casing in thrusting relation to said stationary sealing ring means to secure said stationary sealing ring means in the casing.

' RUSSELL R. CURTIS.

RICHARD L. GATES.

REFERENCES CITED The following references are of record in the ille of this patent: 

